Electric shot-firing device



Oct. 11 1927.

A; J. MARSHALL ELECTRIC SHOT FIRING DEVICE FiledMarch 1926 Inventor A.J. MARSHALL ELECTRIC SHOT FIRING DEVI'QE Oct. 11, 1921 644,843

Filed March 8, 1926 2 Sheets-Sheet 2 Inventor Attorney Patented Oct. 11,1927.

NTTED STAT EJS MARSHALL, GE HARB'ISBUEG, ILLINOI S, ASSTGNOE OF ONE-EAL?T GEORGE "W. MITCHELL, -OF"HARRISBURG, ILLZNGIS.

. 1,644,843 PATENT OFHQE;

ELECTRIC SHOT-FIRING DEVICE.

Application filed- March a, 1926. Serial No. 93,284.

The present invention relates to an electric shot firing device designedfor use in firing shots in mines. The device is exceedingly simple inits construction, efficient and reliable in its operation, durable, notlikely to easily become out of order, and otherwise well adapted to thepurp se for which it is desigl'ied.

There have been chines designed by others electric shot firing. mabut inallof then. with which I aim-familiar, there is required an excessiveamount of wires to operate them, whereas in the machines described in.this application, only two wires are necessary and as many machines maybe placed in the line as desired.

lVith amine equipped with thesema chines, any number of shots in anynumber of rooms can be fired from the surface with only two wiresleadingto-the first machine, and with only two wires from that machine to theothers in series. With these machines, the shots are firedat intervals,and: the intervals between the shots can be regulated as, desired.

With the above and numerous other objects in view ,as will appear as thedescrip- ,tion proceeds, the invention resides in certain novel featuresof construction, and invthe combination and arrangement of parts as willbe hereinafter more fully described and claimed.

Inthe drawing Figure 1 is anelevation of one oft-he machines embodyingthe features of my invention,

Fig. thru,

Fig.

Fig. 1 is a bottom plan view in the dash pot, and

Fig. is a diagrammatic view show ng two of the machines wire-din series.

Referring to the construction of oneof the machines, in detail, it willbe seen that 5 designates a base having the rectangular 2 is a verticalsection taken there- 3 1s autop plan view tlllQOL,

of the plunger frame 6 rising therefrom, including two verticalsidera'ils 7 and 8,:and a crosshorizontal rail 9. A-dash pot is seatedon the base 5 and includes a cylinder 10, the bottom end of which isclosed and counter-sunk in the recess 11 of the base 5; The upper end ofthe cylinder is open and provided with extcrnal threads for .detaohablyreceiving a cap 12 havingthe 01f center vent oyeningv 13 and the centeropening 141 This dash pot cylinder 10 is filled with oil as usual.

A plunger 15 is movable in the cylinder 10 and provided with a pair ofopenings 16. A plunger rod 17 is slidable through the. opening 1% of thecap 12,-.and has its lower end reduced to pierce the center oftheplunger 15 and is-helcl in engagement therewith by'a nut 18 or in anyother suitable manner. Adacent the plunger 15,, the rod 17 is providedwith a notch 19. A plate 20 is held assembled in abutmentwith the bottomsurface of the plunger 15 by means of the reduced end of the rod 17 andthe nut 18. This plate is provided with openings 21 registrable with theopenings 16 of the plunger 15. Obviously by shifting the openings'21 inrespect to the openings 16 to vary the amount of registration thereof,the speed of the plunger through the oil in thedash pot cylinder 10 maybe regulated i A bracket 23 is mounted on the cap, 12 and has 'slidablymounted therein a catch 24: which is limited in its'movement by a pinand slot connection 25 with the bracket 23. This catch has -a notch 26which is engage- .able the noseend of a bell crank lever 27 pivoted asat 28 to the bracket 23. An armature 29 is provided 011 the other end ofthe .bellcrank lever for being attracted by an electro-magnet 30 mountedin a bracket 31 ,PBOJQC-iilhg. inwardly from an intermediate portion ofthe side vertical rail 7, said bracket being substantially L-shaped asis indicated to advantage in Fig. .3.

A weight element 32- is fixed to the intermediate portion of the plungerrod 17. An electricity conducting standard 38 rises from the baseb atonecorner thereof. A brush slidably-engages the standard38, A contact. isdisposed on the weight element 32 and is electrically engaged with theother end of the brush'3 l. Both the brush 34 and the contact 35 areinsulated from the weight element- 32 as at36 in any suitable manner.

A stationary spring bottom contact 37 is mounte-don the side verticalrail 8 by a binding post .38. A plurality of intermediate verticallyalined and spaced spring contacts 39, 40 and ll are mounted on:the rail8 above the contact 37by means of aplurality of binding. posts l2, 413and 1 1 respectively. A top spring contact is mountedonthe rail 8 abovethe spring contact ell by means of a binding'post 46.

These contacts v.87 39, 40,

41 and 45 are disposed in the path of move ment of the contact 35.

The upper end of the plunger rod 17 pierces the center of the cross rail9 to be guided thereby. To set the machine, the weight 32 is lifted toits uppermost position at which time the contact 35 engages the contact45 and the catch 24 engages the notch 19. The electro-magnet 30 is thenenergized, attracting the armature 29, rocking the bell crank lever 27,sliding the catch 24 to disengage the notch 19, so that the weightelement 32, rod 17 and plunger 15 slowly gravitate downwardly, the dashpot controlling the speed which may be adjusted as heretofore indicatedby the plate 20.

As the .weight 32 moves downwardly, the contact 35 engages successivelythe spring contact 41, 40, 39, and finally 37,'and remains in engagementwith contact 37 until lifted as heretofore indicated.

To appreciate the utility of this machine, it is necessary to considerseveral of them in circuit, and for this purpose, I have illustrated adiagram in Fig. 5. The numeral denotes the positive line and the numeral51 the negative line. These power lines may be connected with anysuitable source of electrical energy and sufficient voltage may beobtained for the shot firing from a plu rality of dry cells ifpreferred. A plurality of wires 52 and 52 lead from the line 50thrufuses 53 and 53 to standards 33 and 33 of two different machines inthe present illustration. The wiring of two machines will be sufficientto give a clear understanding as to the wiring of any number ofmachines. A wire 54 leads from the line 51 to the electro-magnet 30 andhas a switch 55 therein. A wire 54 leads from the line 51 to theelectro-magnet 30.

A wire 56 connects the contact 45 with the electro-magnet 30. A wire 57connects the contact 37 with the electro-magnet 30. A wire 57 connectsthe contact 37 with the electro-magnet of the next machine, not shown.The contacts 41, 40, 39 are connected respectively to cartridges, A, Band C, by suitable wires 58, while contacts 41, 40, and 39 are connectedto cartridges A", B5 and C in another room of the mine by suitable wires58. Vires 59 and 60 lead from the cartridges A, B and C to the negativeline 51, while wires 59 and 60 lead from the cartridges A, B andC, tothe negative line 51.

l Vhen the two machines are wired as detailed above, it will be seenthat at the end of the day after the miners have left the mine, theweights carrying the brush 34 and 34 and the contacts 35 and 35 will belifted as heretofore indicated. After all the miners have left the mine,the switch 55 is closed, so that the current will flow from the line 50through wire 52, fuse 53, standard 33, brush 34, contact 35, contact 45,and wire 56 through electro-magnet 30, through switch 55, and wire 54 tothe line 51. This causes the energization of magnet 30, so as to releasethe plunger rod as heretofore indicated, thereby causing the contact 35and brush 34 to move downwardly until-the contact 41 is engaged, causingthe current from the standard 33 to flow through the cartridge Aexploding the same. hen in like manner, as the contact 35 en agescontacts 40 and 39 successively, cartridges B and C will be fired. Whenthe contact 35 reaches the contact 37, the current flows through thewire 57 for energizing the electro-magnet 30 for releasing the weight ofthis machine to allow the contact 35 and 34 to move downwardly, andengage successively the contacts 41, 40, 39, for energizing andexploding successively cartridges A, B and C. Thus any number of themachines may be wired in series, it being only necessary to use twopower lines 50 and 51. No two cartridges will be exploded at the sametime, and no two rooms will have cartridges exploding at the same time.

It is preferable that the plate 20 may be made of spring metal or otherresilient material so that it will be capable of flexing away from theplunger 15 on the upward stroke thereof so that the oil may rush freelythrough the openings 16 which are relatively large in comparison to theopening 21. This feature is provided for the obvious purpose of quicklysetting the machine.

It is thought that the construction, operation, and advantages of thisinvention will now be clearly understood without a more detaileddescription thereof. The present embodiment of the invention has beendisclosed in detail, since in actual practice it attains the features ofadvantage enumerated as desirable in the statement of the invention andthe above description. It is apparent that numerous changes in thedetails of construction, in the materials, and in the combination andarrangement of parts may be resorted to without departing from thespirit or scope of the invention as hereinafter claimed, or sacrificingany of its advantages.

Having thus described niy invention, what I claim as new is 1. A deviceof the class described including in combination, a base, a pair ofvertical rails rising from the base in spaced relation, across railconnecting the upper ends of the vertical rails, a plurality of springcontacts onone of the vertical rails, a conductor stai'ida'rd risingfrom the base, a dash pot cylinder on the base, a plunger in the dashpot cylinder having an opening. a plunger rod piercing the plunger andris ing therefrom and piercing the cross rail, a spring plate pierced bythe plunger rod, and

having an opening registrable with the opening in the plunger, means forholding the rod in engagement with the plunger, and the plate adjustedas to the amount of registration of the two openings,-a weight elementon the rod, a contact on the weight element engageable with the springcontacts, a brush engageable with the contact on the weight element andslidably engaged with the standard, a bracket projecting from the othervertical rail, an electro-magnet mounted in the bracket, a bell crankpivoted on the dash pot cylinder and having an armature at one endassociated with the electromagnet, and a catch slidable on the cylinder,and engageable with a notch provided in the rod adjacentthe plunger.

2. A device of the class described inchiding, in combination, a base, aframe rising from the base, a plurality of spring contacts arranged onthe frame in spaced relation to one another, a conductor standard risingfrom the base, a dash pot cylinder on the base, a plunger in the dashpot cylinder, means associated with the plunger for regu lating thespeed thereof in the cylinder, a plunger rod engaged with the plungerand rising therefrom, a weight element on the rod, a contact on theweight element engageable successively with the spring contact, a brushengaged with the contact on the weight element and slidably engaged withthe standard, an electro-magnet, an armature associated with saidelectro-mag net, a. catch engageable with a notch provided in the rodfor holding the plunger raised in the dash pot cylinder, and meansassociated with the catch and armature whereby when said armature isattracted by the electro-magnet, said catch is released from the notchof said rod to allow the weight element to move downwardly forsuccessively engaging the contact thereon with the spring contact.

3. A device of the class described, including, in combination, a frame,a plurality of a ing contacts arranged on the frame in vertical spacedrelation, a dash pot cylinder mounted in the frame, a plunger in thedash potcylinder, a rod rising from the plunger, a weight element on theplunger, acontact on the weight element successively engageable with thespring contact, a conductor standard, a brush engaged with the contacton the weight element and slidably engaged ith the standard, means fornormally holding the weight element and rod and plunger in a raisedposition. and an electroanagnet and armature for releasing said means.

4. A device of the class described including, in combination, a frame, aplurality of spring contacts arranged in vertical spaced alinement onthe frame, a conductor standard rising alongside of the frame, a dashpot cylinder in the frame, a plunger in the dash pot cylinder, a plungerrod engagea ble with the Jl-UH GI and rising therefrom in the frame, aweight elei'nent on the rod, a contact on the weight element engagcablesuccessively and selectively with the spring contacts, a brush engagedwith the Contact of the weight element and slidably engaged with thestandard, a bracket on the dash pot, a catch slidable 111 the bracketand engage able with a notch provided in. the rod for holding said rodin a raised position, means for limiting the movement of the catch, abell crank pivotally mounted in the bracket and engaged at one end withthe cat-ch for ii-nparting sliding 'movement thereto, an armature at'theother end of the bell-crank, and an electro-magnet associated with thearmature so that when energized, the armature will be moved to rock thebell crank and to release the catch from the notch of the .rod. 5.A'device of the class described includmg 111 combination, a frame, aplurality of sprmg contacts arranged in vertical spaced alinement on theframe, a conductor stand ard rising alongside of the frame, a dash potcylinder in the frame, a plunger in the dash pot cylinder, a plunger rodengageable with the plunger and rising therefrom, in the frame a weightelement on the rod, a contact on the weight element engageablesuccessively and selectively with the spring contacts, a brush engagedwith the contact I of the weight element and slidably engaged with thestandard, a bracket on the dash pot, a catch slidable in the bracket andengage able with a notch provided in the rod for holding said rod in araised position, means for limiting the movement of the catch, a bellcrank pivotally mounted in the bracket and engaged at one end with thecatch for lmparting sliding movement thereto, an armature at the otherend of the bell crank, an electro-magnet associated with the armature sothat when energized, the armature will be moved to rock the bell crankand to release the catch from the notch of the rod, the plunger beingprovided with an opening, a spring plate on the bottom of the plungerhaving an opening registrable with the opening of the plunger, means foradjusting the plate to regulate the amount of registration of the twoopenings, said plate being adapted to flex away from the plungerwhen-said plunger is moved upwardly in the dash pot cylinder.

6. A device of the class described including, in combination, a base, apair of vertical rails rising from the base in spaced parallel relation,a cross rail horizontally disposed and connecting the upper ends of thevertical rails and provided with an opening, a plurality of springcontacts on one of'the vertical rails, a conductor standard rising fromthe base in spaced parallel relation to from the base having its upperend open and externally threaded, a cap threadedly' engaged on the upperend of the dash pot cylinder, and having a central opening and an offcenter vent opening, a plunger in the dash pot cylinder, having a pairof openings oif center thereof and an opening in the center thereof, aplunger rod piercing the center opening of theplunger and risingtherefrom, piercing the center opening of the cap and the opening of thecross rail, a spring plate having a central opening pierced by theplunger rod, said spring plate being held in abutment with the lowersurface of the plunger, said spring plate provided with openings at itsends registerable with the off center openings in the plunger, a nut onthe end of the plunger rod for holding the plunger rod assembled withthe plate and the plunger, and to allow adjustment of the plate inrespect to the plunger, a weight element on the rod above the dash pot,a contact on the weight element engageable selectively and successivelywith the spring contacts, a brush engaged with the contacts on theWeight element and ,slidably engaged with the standard, a bracketprojecting from the other vertical rail, an electro-magnet mounted onthe bracket, a bracket on the top of the dash pot cylinder, a bell crankpivoted in the last mentioned bracket, a cat-ch slidabl-e in the lastmentioned bracket and'having a notch engaged by one end of the bellcrank, means forlimiting the movement of the catch, said rod providedwith a notch adjacent the plunger adapted to be engaged by said catchfor holding said plunger in a raised position in the dash pot cylinder,an armature at the other end of the bell crank associated with theelectromagnet.

In testimony whereof I affix my signature.

ANDREWV J. MARSHALL.

